Gunze Limited

Ube Industries, Inc.

Naoki Nishiura

Takashi Kuraoka

Junya Kanetake

Toru Murakami

Tsutomu Yoshida

Tsuneo Miyamoto

Naoyuki Maruichi

Akira Ichino

Nobuaki Kobayashi

Takeshige Nakayama

Tetsuo Sadamitsu

The present invention provides a carbon black-dispersed polyamic acid solution composition having a high solids content and a high carbon black content. The invention further provides an intermediate transfer belt using the polyamic acid solution composition. The carbon black-dispersed polyamic acid solution composition is obtained by uniformly dispersing carbon black in a polyamic acid solution obtained by reacting biphenyltetracarboxylic dianhydride and an aromatic diamine in an organic polar solvent. The biphenyltetracarboxylic dianhydride includes 2,3,3',4&#x2032;-biphenyltetracarboxylic dianhydride and 3,3&#x2032;,4,4&#x2032;-biphenyltetracarboxylic dianhydride. The aromatic diamine includes 4,4&#x2032;-diaminodiphenyl ether and p-phenylenediamine. The polyamic acid solution has a solids content of 25 weight % or more.

Polyamic acid solution composition having carbon black dispersed therein, process for production of semiconductive polyimide resin belt using the composition, and semiconductive polyimide resin belt

A semiconductive polyimide resin belt that exhibits excellent electrical properties, including the ability to achieve accurate image transfer in a color image-forming unit, and the ability to prevent variations in resistance due to the transfer voltage, enabling high-quality transfer images to be stably produced over an extended period of time; and excellent physical properties, including resistance to deterioration in flatness due to plastic deformation caused by loads applied in the width direction of the belt, excellent durability, and stable operation even after extended use; and an intermediate transfer belt made of the semiconductive polyimide resin belt. The semiconductive polyimide resin belt comprises carbon black and a polyimide resin. The polyimide resin is obtained by imidization of terphenyl-3,3',4,4&#x2032;-tetracarboxylic dianhydride and an aromatic diamine component containing 50 mol % or more of an aromatic diamine having 3 and/or 4 aromatic rings based on a total amount of the aromatic diamine component.

Semielectroconductive polyimide resin belt and process for producing semielectroconductive polyimide resin belt

The present invention provides a method for producing a high-quality nonconductive or semi-conductive seamless (jointless) tubular polyimide film in a simple, efficient, and economical manner, and the like. More specifically, the invention relates to an electrically non-conductive or electrically semi-conductive seamless tubular polyimide film comprising polyimide having at least two aromatic tetracarboxylic acid derivatives comprising 15 to 55 mol % of asymmetric aromatic tetracarboxylic acid component and 85 to 45 mol % of symmetric aromatic tetracarboxylic acid component and at least one aromatic diamine component, in which, as required, a specific amount of carbon black is dispersed, and relates to a method for producing the same.

Endless tubular polyimide film

A carbon black-dispersed polyamic acid solution composition that utilizes carbon black excelling in safety and environmental adaptability and excels in the dispersion stability and fluidity of carbon black dispersed in polyamic acid solution, and that realizes high solid content and high carbon black content. An intermediate transfer belt of polyimide, which produces a transfer image of high quality in a color image-forming apparatus, produced from the polyamic acid solution composition. In particular, a carbon black-dispersed polyamic acid solution composition containing a polyamic acid solution obtained by reaction of approximately equimolar amounts of biphenyltetracarboxylic acid dianhydride and an aromatic diamine, and containing a carbon black of 2 to 6% volatile content produced by oil furnace process, wherein the solid content of the solution composition is 23 wt. % or more and wherein the carbon black content of the solid is in the range of 20 to 30 wt. %.

Carbon black-dispersed polyamic acid solution composition, and process for producing semiconductive polyimide resin belt therewith

The present invention provides an electrically-semiconductive poly(amic acid) liquid composition and a use thereof. An electrically-semiconductive poly(amic acid) (polyimide precursor) liquid composition whose electrical semiconductivity is applied by comprising an electrically-conductive carbon black. Change in an electrical resistivity of the liquid composition after being stored for 180 days at a temperature of 23&deg; C. and in an atmosphere of a RH of 65% is 7% or less based on the electrical resistivity immediately after the preparation of the liquid composition. The electrically-semiconductive poly(amic acid) liquid composition is obtainable by mixing 5-40 parts by weight of a poly(amic acid), 95-60 parts by weight of an organic polar solvent and 10-40% by weight based on the poly(amic acid) of an electrically-conductive carbon black having a volatile content of 5-20%, a specific surface area of 100-300 m,/g and a pH of 2-4. The electrically-semiconductive poly(amic acid) liquid composition is used for molding an electrically-semiconductive seamless tubular polyimide film, for example, which is usable as an intermediate belt member for fixation and transfer of toner in a copying machine.

Electrically-semiconductive poly(amic acid) liquid compositions and their use

A seamless tubular composite film wherein a seamless tubular film comprising fluororesin with a film thickness of 5-20 &mgr;m stretched 2-10% in circumferential direction is fitted on the outside of a seamless tubular film comprising a thermosetting polyimide resin, or the precursor polyamic acid and heated at 200-400&deg; C. for anchorage. In addition, in order to give thermal conductivity and antistatic properties leading to inhibition reduction of heating time and inhibition of adhesion of dirt, boron nitride and compatible thermal conductive agents may be dispersed in the polyimide resin, and carbon black and like electric conductive agent may be dispersed in fluororesin. The film is useful as toner fusing member, such as in electrophotographic copying machines and in laser printing.

Seamless tubular composite film and method for producing the same

The present invention relates to a heat-conductive polyimide film comprising a heat-conductive powder dispersed therein with a concentration gradient. The film can be produced, for example, by centrifugal casting. The film can be used as an excellent component or member in those fields in which heat conductivity is required in addition to mechanical characteristics, heat resistance and chemical resistance. For example, it is used as a thermal fixation member in a laser printer.

Growing community of inventors

Moriyama, Japan

Naoki Nishiura